Method of forming and ejecting die castings



Patented Mar. 8, 1949 OFFICE METHOD OF FORMING AND EJECTING DIE CASTINGSLouis H. Morin, Bronx, N. Y.

Application May 26, 1944, Serial No. 537,472

8 Claims. 1

This invention relates to the formation of die castings, such forexample, as scoops on a mounting tape in forming separable fastenerstringers. More particularly, the invention relates to a novel method ofarranging cavities or impressions in the dies movable toward and fromeach other in a common plane so that after a casting has been formed inthe cavities or impressions, separation of said dies will operate toautomatically eject the castings from the cavities or impressions,moving the castings at right angles to the line of movement of the diesin this operation. Still more particularly, the invention deals with theformation of castings having angularly disposed wall portions extendingdivergingly from the longitudinal center of the castings or from theparting line of the dies when the latter are in closed position, and inutilizing these surfaces in cooperation with the walls of the cavitiesof the dies forming such surfaces in ejecting the castings and movingthem relatively to the dies. The novel features of the invention will bebest understood from the following descriptions when taken together withthe accompanying drawing, in which certain embodiments of the inventionare disclosed, and in which the separate parts are designated bysuitable reference characters in each of the views; and in which:

Fig. 1 is a sectional view through the coupling end portion of a fewscoops of a stringer, showing a pair of dies used in castingone of thescoops on the stringer tape.

Figs. 2, 3 and 4 are views similar to ig. 1, showing different positionsof the dies in separation thereof and in ejectingthe casting from thecavities or impressions of the die, and also illustrating the movementof the casting angularly to the dies or the direction of movementthereof.

Fig. 5 is a longitudinal detailed sectional view showing one scoop asapplied to a stringer tape with the die omitted; and

Fig. 6 is a view similar to Fig. 2, showing the invention applied to atwo cavity die.

In the formation of die castings, it has been customary to provide diecavities limited to such configurations as permit the dies to be drawnoff the casting, while the latter is stationary, by movement of the diesaway from each other in opposite directions in the same line (forconsulting castings, or in other words, castings having recessedsurfaces, with the greatest depth of the recess centrally of the castingand at the parting line of the dies, for example, in forming a castingof substantially V-cross sectional form, as hereinafter more fullydescribed.

With castings of this type and kind, I have conceived a method formingthe subject matter of a separate application of moving the, dies towardand from each other at an angle common to the angle of inclination ofthe diverging walls forming the recess or undercut portion of theresulting casting. The application in question constitutes applicationSerial Number 546,180, filed July 22, 1944, now Patent No. 2,426,408,for a patent on Method of forming undercut die castings.

With the present invention, however, I have conceived the possibility offorming undercut portions in castings of the kind under considerationand by movement of the dies toward and from each other in a common planein accordance with the conventional and well known methods, I canutilize that portion of the die cavities forming the undercut in theresulting casting as the means to eject the casting from the diecavities, and also to feed the casting at right angles to the line ofmovement of the dies toward and from each other. By reason of this novelmethod, undercut castings can be formed, and the castings simply andeasily ejected from the die cavities actually in a manner which issimpler and more positive than with the use of ejector pins, as commonlypractised in the die casting art for ejecting conventional non-undercutcastings from the die cavities.

The present invention also deals with the method of producing scoops forseparable fastener stringers of what I term the coreless type, in otherwords, dispensing with the use of conventional core pins for formingsockets or female coupling portions in parts of the scoops. From thisstandpoint, the invention deals with scoops such as of the type and kindmore fully and completely disclosed in my prior application SerialNumber 531,618, filed April 18, 1944.

While the invention generally speaking deals with the formation of diecastings, and particularly castings formed on mounting members, in orderto illustrate one adaptation of the invention, Ihaveshown it appliedtothe formation of die cast scoops, such for example, as the scoops H) onthe edge of the stringer tapes II. The scoops in question are of the typand kind which I term coreless scoops, where no core pins or the likeare necessary to form the desired contour in the coupling end portionsof the scoops. The scoops are of substantially V- cross sectionalcontour, or as seen in the drawing inverted V-cross sectional contourhaving the diverging coupling side portions I2 and I3, which sideportions have lower diverging walls or surfaces l4 and correspondingupper surfaces I5, the latter being slightly contracted or tending toconverge with the angularity of the walls [4. This cross sectionalcontour forms an undercut longitudinal channel or recess l6 on the lowersurfaces of the scoops, and a corresponding longitudinal ridge I! at theupper surface thereof.

Considering Fig. of the drawing, it will also appear that the couplingend portion of the scoop has on upper and lower surfaces transverserecesses l8 and i9, outwardly of which are corresponding projectingmembers 20 and 2|, these latter recesses and projections forming betweencoupled scoops of opposed stringers the means for preventing lateralseparation of the stringers, whereas the V or inverted V-cross sectionalcontour of the scoops will retain coupled scoops against transverseseparation, as more specifically dealt with in the applicationhereinbefore identified.

In Fig. 5 of the drawing 22 represents the gate portion of the castingwhich is removed in' the completion of the formation of the stringers.This gate is, as in other constructions of this kind, arranged on theparting line 23 of two relatively movable dies 24 and 25, the dies 24and 25 have on adjacent surfaces thereof an opening, and registering atthe parting line 23, cavities or impressions 26 and 21. The lowersurfaces 28 of these cavities form the surfaces I4 of the resulting castscoops, whereas the surfaces 29 form the upper surfaces l5 of the castscoops, as will clearly appear from a consideration of Fig. l of thedrawing.

The illustrations in Figs. 2, 3 and 4 of the dies 24 and 25 arediagrammatic from the standpoint that the complete contour of the diecavities is not shown, as it would appear in the background, for theformation of the irregular contour defined by the recesses l8 and i9 andprojections 20 and 2|. This is done to simplify the showing, as theseviews become much clearer in illustrating the more important phase ofthis conception which deals with the election of the castings from thecavities 26 and 21. It is sufficient for present purposes to note, asclearly illustrated and described in the above identified copendingapplication, that while the thickness of each scoop varies throughoutits length, each crosssection, no matter where taken in the length ofthe scoop, is of V-shape. Hence the die cavity sections in planes otherthan but parallel to those illustrated in the accompanying drawings,differ therefrom only in the thickness of the side portions of the V.Accordingly, the below described operation in relation to the sectionsillustrated serves equally well for any other selected section.

After a casting has been formed, as illustrated for example in Fig. 1,the dies 24 and 25 are then separated in the direction of the arrows 3B,which appear in Figs. 2, 3 and 4 of the drawing. These three figuresshow three stages of movement of the dies away from each other in adirection normal to the parting line of the dies to show how in thesestages of operation the resulting casting is moved upwardly in thedirection of the arrows 3| in said figures, or at right angles to thepath of movement of the dies from each other.

In this operation, the surfaces 28 act as cams moving along the surfacesl4 of the casting, and thus force the casting upwardly until, as seen inFig. 4, the casting is entirely out of the die cavities, at which timethe casting may then be offset downwardly together with the tape il inthe direction of the arrow 32, Fig. 4, to bring the next section of thetape II in position to receive the next successive casting, and then theabove operation is repeated.

In the above ejection operation, it will appear that the upper surfacesl5 of the casting immediately become free of the surfaces 29. In otherwords, these surfaces do not interfere with or hinder the upwardmovement of the casting. This is facilitated by the fact that thesurfaces 28 and 29 are diverging with respect to each other in thedirection of the outer or abutting surfaces of the dies. In thisconnection, it will be understood that as long as the upper wallstructure of the die cavity does not interfere with the upward movementimparted to the casting, or

in other words, as long as these upper surfaces are free of the casting,the described operation of ejection will take place.

In the method of automatically forming successive die castings on amounting member, in addition to feeding the mounting member stepby-stepin one direction with respect to the dies to bring the successivesections of the member in position to receive the dies, with my newmethod, the mounting member also has an intermittent feed, namely thefeed which takes place for ejecting the casting. In the particular ap:plication illustrated it is preferred that this inter mittent ejectingfeed be in a reverse direction to the said step-by-step feed, and theextent of this reverse feed will be equal to the depth of the undercutemployed, thus the deeper the undercut the greater the feed. In anautomatic die casting machine of the kind under consideration, meanswill be provided for feeding the tape into position for receiving thenext successive casting, and this feed may also operate to feed the tapein the reverse direction consistent with the reverse feed of the castingin ejecting the casting from the dies.

In Fig. 6 of the drawing is shown a slight modification wherein twocastings l0, identical with the castings Ill shown in Figs. 1 to 5inclusive are simultaneously formed between relatively movable dies 33and 34 which are generally similar to the dies 24 and 25, excepting thateach die 33 and 34 will have a pair of cavities 35 and 36, thus formingthe two castings l0 simultaneously on the tape ll, otherwise the methodof procedure is identical with that shown in Figs. 2 to 4 inclusive, theshowing in Fig. 6 being similar to that of Fig. 2. The only otherdifference in the two methods would be that with the construction shownin Fig. 6, the tape feed mecha nism would operate to feed the tape agreater distance in the direction of the arrow 32 in order to bring twonew sections of the tape in position to receive the next successive pairof castings. From this standpoint, it will be understood that anydesired number of castings may be simul taneously formed on the tape ormounting member, or in other words, formed in a single castingoperation, and regardless of the number of castings formed, the backfeed in the ejection of the castings from the die cavities will be nogreater thanin ejecting a single casting, but the normal tape feed forspacing the tape or mounting memberwill be followed to suit the numberof castings being formed.

In the more general uses of the invention, it will be apparent that anyundercut casting may be formed between dies operated in the mannerherein described and automatically discharged or ejected in theseparation of the dies as long as the castings are of such contour as tootherwise free themselves from the die cavities and have no wallstructures on surfaces thereof opposed to the undercut surfaces whichwould have the tendency to lock the castings in the dies, or in otherwords, lock the dies against separation.

From this standpoint, it is well to state that to the skilled mechanicconsideration of the structure as shown in Fig. 1 of the drawing wouldappear toshow or illustrate a casting locked within the dies so that thedies could not possibly be separated. However, the illustrations inFigs. 2, 3 and 4 of the drawing clearly show that by allowing thecastings to move or be fed relatively to the die movement, thesecastings will be automatically ejected from the die cavities. It willalso be understood that it is immaterial in which direction the castingis fed in ejecting the same from the die. Here the illustration in theaccompanying drawing is simply to be consistent with conventionalpractises in the formation of separable fastener stringers. It will bemore definite to state that the castings are moved, in the ejectionthereof, in the direction of the surface opposed to the undercut surfaceof the casting.

It is to be understood that the invention is not limited to an undercutin the casting where the greatest depth of the undercut is centrally ofthe casting or at the parting line of the dies. In some instances and byreason of other cross sectional contours of the undercut portion, thedies may be required to move a greater distance in separation, in orderto clear the casting, than would be required by the length of theundercut portions at the sides of the castings, but in all instances,the castings are moved in the direction indicated to the degreecorresponding to the depth of the undercut, or at least the deepestundercut in the casting. Here it will also be kept in mind that one sideportion of the casting may have an undercut deeper than that of theother side portion thereof.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. The method of forming die cast scoops of separable fastener stringershaving undercuts on one surface thereof, which comprises moving a pairof movable dies toward each other and a tape in a common plane, forminga cast scoop in undercut cavities on adjacent surfaces of said dies andon said tape with the dies in closed position, forming by said undercutcavities an undercut recess longitudinally of one surface of the scoop,and then separating said dies and coincidently ejecting the casting fromthe die cavities at right angles to the path of movement of the dies bymoving that part of the wall structure of said cavities forming theundercut recess in said casting at an angle to the walls of said recess.

2. The method of forming die cast scoops of separable fastener stringershaving undercuts on one surface thereof, which comprises moving a pairof movable dies toward each other and a tape in a common plane, forminga cast scoop in undercut cavities on adjacent surfaces of said dies andon said tape with the dies in closedposition, forming by said undercutcavities an undercut recess longitudinally and throughout the entirelength ofone surface of the scoop, then separating said dies andcoincidently ejecting the casting from the die cavities at right anglesto the path of movement of the dies by moving that part of the wallstructure of said cavities forming the undercut recess in said castingat an angle to the walls of said recess, and then feeding the tape tobring the next section thereof in position to receive the nextsuccessive cast scoop.

3. The method of forming successive die castings, which comprisesforming a casting between diesmovable toward and from each other in acommon plane, the dies having cavities shaped to form undercut cammingsurfaces therein and to produce undercut camming surfaces on theresulting casting, and ejecting the casting from the die cavities duringthe separation of the dies by moving the cam surfaces of the diecavities at an angle to the cam surfaces of the casting, thus cammingthe casting out of the dies in a different direction from the path ofmovement of the dies.

4. The method of forming successive die castings, which comprisesforming a casting on a mounting member between dies movable toward andfrom each other in a common plane, the dies having cavities shaped toform undercut camming surfaces on the dies and to produce (:0- actingundercut camming surfaces on the resulting casting, ejecting the castingfrom the die cavities during the separation of the dies by moving thecam surfaces of the die cavities at an angle to the coacting camsurfaces of the castings and thus moving the casting relative to thedies by virtue of a cam action, and feeding said mounting member in areverse direction to said movement of the casting to space successivecastings on said member.

5. The method of forming successive groups of die castings, whichcomprises forming a group of die castings on a mounting member betweendies movable toward and from each other in a common plane, the dieshaving groups of cavities, each casting in the group having undercut camsurfaces formed by corresponding surfaces in the die cavities, ejectingthe group of castings from the die cavities during the separation of thedies by moving each die at an angle to the undercut cam surfaces of thegroup of castings so as to force the latter cam surfaces to coincidentlyuse and ride over the cam surfaces of the die cavities and thus move thecastings in the direction of the surfaces opposed to the undercutsurfaces of the castings, and then feeding said member relatively to thedies to space successive groups of castings on said member.

6. The method of forming a casting by means of a pair of dies movabletoward and from each other in a direction substantially normal to theirmating surfaces, the mating surfaces of the dies having registeringcavities partially defined by having a central longitudinal ridgetherein, which comprises injecting casting material into the diecavities with the dies in closed position to form a casting having alongitudinal valley defined by said ridge, then separating the dies andmoving the ridge portions of the dies over the valley surfaces of thecasting to move the casting 7 ing for movement relatively to said dieswhen in separated position.

'7. In the formation of die cast scoops of separable fasteners by meansof separable dies having mating cavities including surfaces extending atsuch angles with respect to the parting line of the dies as together toform an undercut recess on one face of the scoop cast in such cavitiesand a complementary ridge on the opposite face of the scoop, saidundercut recess being defined by walls angularly disposed relative tothe parting line of the dies, the method of forming a succession ofspaced scoops on a stringer tape, which includes the steps of closingsuch dies on the tape, filling the cavities with casting material,withdrawing the dies from their parting line in a direction normal tosuch line and simultaneously therewith moving the cast scoop and thetape in a difierent direction by virtue of a camming action exerted bythe angularly extending surfaces of the die cavities against theangularly disposed walls of the undercut recess of said scoop.

8. In the formation of die cast scoops of separable fasteners by meansof separable dies having mating cavities including surfaces extending atsuch angles with respect to the parting line of the dies as together toform in such cavities a scoop having an undercut recess bounded byangular walls on one face of the scoop and a com plementary ridge on theopposite face of the of said scoop.

LOUIS H. MORIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 488,570 Miller Dec. 27, 1892548,895 Staples Oct. 29, 1895 1,370,192 Crate Mar. 1, 1921 1,609,460Buttles Dec. 7, 1926 2,218,091 Marinsky et al Oct. 15, 1940 2,263,037Gits Nov. 18, 1941 5 2,322,908 Poux June 29, 1943 2,355,846 BrundageAug. 15, 1944 2,365,764 Kastner Dec. 26, 1944 FOREIGN PATENTS 30 NumberCountry Date 625,209 Germany Feb. 6, 1936

